Spatial-resolved X-ray photoelectron spectroscopy of Weyl semimetal NbAs

TL;DR

This study employs X-ray photoemission electron microscopy and spectroscopy to analyze the surface composition and electronic states of the Weyl semimetal NbAs, revealing surface oxides and Nb-rich regions.

Contribution

It provides spatially-resolved surface chemical analysis of NbAs, highlighting surface oxides and compositional asymmetry using advanced microscopy and spectroscopy techniques.

Findings

Surface contains Nb and As oxides and bulk states.

Surface is Nb-rich and shows contrast in XPEEM images.

Surface composition varies across different regions.

Abstract

We utilized X-ray photoemission electron microscopy (XPEEM) and X-ray photoelectron spectroscopy (XPS) to investigate the crystal surface of Weyl semimetal NbAs. XPEEM images present white and black contrast in both the Nb 3d and As 3d core level spectra. Surface-sensitive XPS spectra indicate that the entire surface of the sample contains both surface states of Nb 3d and As 3d, in form of oxides, and bulk states of NbAs. Estimated atomic percentage values nNb/nAs suggest that the surface is Nb-rich and asymmetric for white and black areas.